Add logging to help debug b/200572078.

Bug: 200572078
Test: ran launcher and checked logs
Change-Id: If59d850021df226d645aa6a72da2b5bb7ec63782
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 409ee83..467e080 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -2124,6 +2124,10 @@
 
         IntSet result = new IntSet();
         if (visibleIds.isEmpty()) {
+            if (TestProtocol.sDebugTracing) {
+                Log.d(TestProtocol.NULL_INT_SET, "getPagesToBindSynchronously (1): "
+                        + result);
+            }
             return result;
         }
         for (int id : orderedScreenIds.toArray()) {
@@ -2144,6 +2148,10 @@
             // pages being hidden in single panel.
             result.add(pairId);
         }
+        if (TestProtocol.sDebugTracing) {
+            Log.d(TestProtocol.NULL_INT_SET, "getPagesToBindSynchronously (2): "
+                    + result);
+        }
         return result;
     }